A high-speed hetero-junction bipolar transistor (HBT) utilizes a thin extrinsic base region and even thinner intrinsic base region. The fabrication of a high-speed HBT is complicated by the need to control the dopant profiles of the semiconductor dopants in these thin base regions. If the intrinsic base diffusion becomes too wide, the speed of the HBT decreases. If the intrinsic and extrinsic base regions do not link, then the gain of the HBT decreases. Current fabrication techniques do not adequately address both of these problems. Therefore, there is a need for a method of fabricating HBT devices that provides intrinsic base width control and intrinsic and extrinsic base linking.